This invention relates to the provision of an elastomeric and intumescence interface which is capable of providing fire insulation between a combusting solid fuel material and a nearby wall of a container which is holding this material. A preferred embodiment of the invention is described herein in conjunction with such an interface, and with the creation of such an interface, which exists between solid fuel which is used in a rocket, and the surrounding wall, typically the rocket wall itself, which contains this fuel.
There are certain situations, such as the one set forth generally above with respect to a solid-fuel rocket, wherein an interface or a zone of proximity exists between a solid combustible fuel material which is combusting during a rocket launch, and a container wall for that material which needs to be protected against fire damage and potentially catastrophic destruction during such fuel combustion.
In the field of solid-fuel rockets, it is apparently a conventional practice to line the inside wall of a solid fuel-containing compartment with an elastomeric sheet material interface which is referred to, and functions, as an ablative material. Such sheet material is typically installed the form of in predefined-outline sheets (i.e., sheets with defined lateral edges), bonded to the inside surface of the subject wall which is to be protected, with obvious seams existing where the edges of adjacent sheets come together. Experience over the years in this setting has been decorated with a number of catastrophic failures where, during solid-fuel combustion, the intended protective sheet-layer which lies between the combusting fuel and the nearby containing wall fails for one reason or another, perhaps because of seam failure (i.e., seam opening, and resultant exposure of the container wall to the extraordinary heat of fuel combustion).
The present invention provides a resolution to this issue by furnishing a special elastomeric coating which may be sprayed into place as one continuous coating which offers no seams for breaching, and which responds with intumescence behavior (a material-swelling behavior) in response to exposure to high heat, such as fuel combustion. This intumescence heat-response behavior acts quickly, effectively and elastomerically to insulate a protected wall from the intense combustion heat, such as that which is experienced during launch in and of a solid fuel rocket. No coating/layer seams exist to open, and the coating, which follows natural wall expansion with sympathetic, elastomeric coating expansion, also grows progressively in thickness, by way of intumescence behavior, to distance the high-heat fuel-combustion zone from the vulnerable container wall. Various intumescence materials, some of which are mentioned herein, and one of which—sodium silicate—is preferably employed, may be used within the coating of this invention to invoke the desired coating-intumescence behavior.
If desired, the intumescence-armed coating interface of this invention may additionally be strengthened and stabilized by the inclusion in the coating of embedded fibrous contents, such as glass or Kevlar® strands/whiskers.
The various important features and advantages which are offered by the present invention, from both a structural and a methodologic point of view, will now become more fully apparent as the detailed invention description which is presented below is read in conjunction with the accompanying drawings.